A collection of implantable devices used to redirect the angle of growth of long bones in paediatric patients where the growth plates (epiphysial cartilage) are not fused, to allow for the gradual correction of congenital or acquired deformities (e.g., valgus, varus, or flexion deformities of the knee, ankle, or elbow). It typically includes various-sized sheets of surgical steel or titanium alloy, and bone screws to attach the sheets to the bone surface over the growth plates. The screws may be allowed to swivel in their position so that the implant acts like a hinge, permitting growth at the growth plate to gradually straighten the limb.